FIGURE 5.

Decreased sialoside expression in the kidney results in dysfunction, proteinuria, and lethality. A, average body weight of mice (n = 44 to start the experiment) treated with a single intravenous injection of 300 mg·kg⁻¹ 3F-NeuAc reveals a phase of weight gain followed by substantial weight loss. The data represent the means ± S.E. and are representative of three independent experiments. B, survival curve of mice (n = 44) treated with a single intravenous injection of 300 mg·kg⁻¹ 3F-NeuAc demonstrates that all mice died or reached the study end point by day 54. The data are representative of three independent experiments. C, SDS-PAGE analysis of urine over the course of 54 days from mice treated with a single intravenous injection of 300 mg·kg⁻¹ 3F-NeuAc reveals proteinuria, demonstrated by the excretion of large quantities of albumin into the urine. D, SDS-PAGE analysis of urine pooled from mice that received one of the indicated single doses of 3F-NeuAc, ranging from 10 to 300 mg·kg⁻¹. E, hematoxylin and eosin staining shows gross histological changes in the kidney beginning 11 days after a single injection of 3F-NeuAc, tubular protein casts by day 21, and severely distorted glomerular and tubular architecture by day 54. F, immunoblots of whole kidney lysates for podocalyxin on the indicated days following treatment with 3F-NeuAc show the desialylation of podocalyxin and subsequent re-sialylation by day 54. G, immunoprecipitation (IP) of podocalyxin and subsequent Western blotting (WB) with the lectins MAA and PNA demonstrate that podocalyxin sialylation is abrogated in mice treated with 3F-NeuAc.